WOODFORDIN-C, A MACRO-RING HYDROLYZABLE TANNIN DIMER WITH ANTITUMOR-ACTIVITY, AND ACCOMPANYING DIMERS FROM WOODFORDIA-FRUTICOSA FLOWERS

Three new dimeric hydrolyzable tannins, woodfordins A, B and C, along with seven known hydrolyzable tannins, including oenothein B, a dimer exhibiting marked host-mediated antitumor activity, were isolated from an Indonesian crude drug, Sidowayah [dried flowers of Woodfordia fruticosa (L.) Kurz (Lythraceae)]. The structures of the new tannins were elucidated based on chemical and spectral evidence. Woodfordin C, having a macro-ring structure, was also found to exhibit a significant antitumor activity. © 1990, The Pharmaceutical Society of Japan. All rights reserved.